A career intelligence officer has provided PowerPoint slides and other materials to the Washington Post that reveal that the US National Security Agency and the FBI have been tapping directly into the servers of nine US internet companies through a clandestine government program called PRISM. The program was launched in 2007.

Several of the companies told the Guardian, however, that they had never heard of PRISM and had not granted the government secret access to their servers.

"Google cares deeply about the security of our users' data," the search company said in a statement. "We disclose user data to government in accordance with the law, and we review all such requests carefully. From time to time, people allege that we have created a government 'back door' into our systems, but Google does not have a back door for the government to access private user data."

Washington officials have since confirmed the program's existence. A senior White House source told The Associated Press that PRISM involves "extensive procedures, specifically approved by the court, to ensure that only non-US persons outside the US are targeted, and that minimize the acquisition, retention and dissemination of incidentally acquired information about US persons."

James Clapper, the Director of National Intelligence, stressed the point that the program was directed only at foreign terrorism suspects, not average American citizens. In a rare public statement issued Thursday night, the spy chief said that PRISM provided some of "the most important and valuable foreign intelligence information we collect, [which] is used to protect our nation from a wide variety of threats."

Clapper further condemned the leak that revealed the program's existence, claiming that "the unauthorized disclosure of a top-secret US court document threatens potentially long-lasting and irreversible harm to our ability to identify and respond to the many threats facing our nation."

The federal government is allowed to conduct "electronic surveillance" on anyone "reasonably believed" to be outside the United States, according to the Guardian. PRISM enables NSA analysts to grab targeted communications without having to request them from the Internet companies or obtaining individual court orders, the newspaper said.

According to the Washington Post:

It is all the more striking because the NSA, whose lawful mission is foreign intelligence, is reaching deep inside the machinery of American companies that host hundreds of millions of American-held accounts on American soil.

Jameel Jaffer, director of the ACLU's Center for Democracy, told the Guardian that the program was “shocking.”

"The NSA is part of the military. The military has been granted unprecedented access to civilian communications," he said.

"This is unprecedented militarization of domestic communications infrastructure. That's profoundly troubling to anyone who is concerned about that separation."

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